Production methods

Compared to other small fruits, cranberry production is distinctive. This hardy perennial belongs to the ericacæ family and the plants can have a life-span of over 100 years. The cranberry is a plant indigenous to North America. Though it grows naturally in wetlands, the plant is now cultivated in sandy soils which requires proper irrigation. The site must have a naturally elevated ground water level that will not descend lower than 1.2 meters under the growing surface in a draught period. The availability of water is necessary to insure protection of the crop and facilitate harvesting. A vine-like and creeping plant, the cranberry forms runners and upright stems from which grow buds that flower in early summer and consequently grow fruit. These fruits reach maturity between the end of September and beginning of October at which time they are harvested.

Depending on the growth of the buds or fruit, cranberry plants require frost protection when the temperature varies between 1 degree (1°C) and minus five degrees (-5° C) Celsius. It's at this time that a smoothly-running irrigation system is put in action, often during the course of the night in order to protect either the bud, in springtime, or the fruit, during the autumn harvest.

Winter

The cranberry buds form during the fall, so it is very important to protect them during the winter months. Mid-December is the icing period, where the fields are flooded and the plants are covered with a 6-inch coat of protective ice. If exposed to temperatures of -10°C and even less, the fruit-buds risk being killed by the cold.

Once the ice is frozen solid, a thin coat of sand is spread over the fields to regenerate the plants. This phase is called «sanding». It is usually done during the months of January and February every three or four years. In addition to protecting the plants, this practice helps control weeds and harmful insects.

Spring

Once spring arrives, water is drained from the fields and is stored in reservoirs. Sprinklers are re-installed to water the plants in case of frost, which is still frequent at this time of the year. The buds and flowers could be seriously damaged from spring frosts resulting in the death of buds or the loss of flowers. Springtime flooding also has the benefit of fighting certain insects harmful to the cranberry.

During the months of April and May, growers treat their fields in order to attain a proper pH balance. According to soil-analysis performed by agronomists the previous fall, growers administer different doses of specified fertilizers to insure the development of the cranberry plants. Fertilizers (lime, sulfur, and other minerals) are sprayed to insure the land is conducive to production.

When necessary, the cranberry plants are pruned during the course of the spring. Integrated Pest Management against weeds and harmful insects is also implemented throughout the season.

Today, almost the entirety of land dedicated to the cultivation of cranberries is subjected to scouting as well as fertilization monitoring in order to optimize the application of fertilizers and pesticides and to minimize negative impact on the environment. Employing technology such as the use of sexual pheromones to monitor insect behavior is part of the Integrated Pest Management approach. The goal is to track changes in the plants and insects in order to establish protocol that is less harmful to the environment. Integrated Pest Management is implemented according to well-defined standards and specifications.

Summer

Towards the end of spring, the cranberry buds transform into pretty little white and pink flowers. It is then that the pollination period begins. The presence of bees is favorable for the transport of pollen from flower to flower allowing impregnation to occur. The more nectar is gathered from the flowers, the more fruit there will be.

Summer is also a time favorable for an abundance of insects and weeds. Regular scouting becomes necessary to follow the life-cycles of these insects. In organic cultivation, manual weeding is essential to eliminate weeds.

Proper drainage and good irrigation are key elements to insure optimum plant growth. Normally, natural rains are sufficient to meet the water-needs of the cranberry plants. Though cranberries are not cultivated in water, the soil's humidity must be controlled in order for to them to grow; this means that the soil must be well irrigated or well drained, depending on the circumstances. Most growers have a closed water-circuit thereby assuring field irrigation with rain water and melted snow accumulated in their reservoirs.

Autumn

As they mature, the fruits change from white to red, finally becoming a beautiful bright-red color when fully ripe. While they ripen, levels of sugar and anthocyanin in the cranberries increase, making them more resistant to the colder temperatures. Nevertheless, cranberries cannot tolerate temperatures inferior to -4°C depending on the variety. Sprinkling to protect the fruit from frost becomes more frequent during this period. Cranberries hit by a frost become soft and cannot be harvested; this represents a loss of yield to the grower.

In Quebec, the harvest period for cranberries begins in the middle of September and continues through the end of October.